1. Field of the Invention
The present invention relates to imaging systems. More specifically, the present invention relates to duplex printing.
2. Description of the Related Art
Image forming devices, such as printers and copiers, typically apply ink or toner to a media sheet—for example, a pre-cut sheet of paper—to form an image. Such devices may be adapted to form images on both of the opposing sides of the media sheet. This process is commonly referred to as duplex printing. The advantages of duplex printing include reducing the quantity of paper required for a print set as compared to one-sided (simplex) printing, and generating print sets with layouts resembling that of professionally printed books.
Conventional duplex printers require a mechanism—sometimes referred to as a duplexer—which can physically turn the media sheet over. After the sheet is printed on one side by a printing device, the duplexer flips the sheet over and then passes the sheet to either a second printing device or back to the same printing device that was used to print the first side of the sheet for second side printing.
A common method for flipping the media sheet involves diverting the sheet down a dead-end duplexing path, and then reversing the direction of motion of the sheet out of the duplexing path such that the former trailing edge of the sheet becomes the leading edge. Typically, the next sheet must wait until its predecessor has completely exited the duplexer before entering. This requires the gap between pages to be larger than the length of the sheet (assuming common speeds throughout the system). This excessive sized gap decreases sheet throughput and cuts the performance limits of the system in half.
Additionally, most printing technologies require a minimum amount of time to transpire before the image-side of the media can be universally handled, i.e. for second side printing. This can also limit system performance.
Hence, a need exists in the art for an improved system or method for duplex printing which offers greater sheet throughput than prior art methods.